According to the latest global estimates, 493,000 new cases of cervical cancer occur each year among women, and 274,000 women die of the disease annually (Jacques Ferlay et al., 2002, GLOBOCAN). Because the disease progresses over many years, an estimated 1.4 million women worldwide are living with cervical cancer, and two to five times more, or up to 7 million women worldwide, may have precancerous conditions that need to be identified and treated (Ferlay et al. 2002, GLOBOCAN; Bosch et al. 2002, J Clin Pathol. 55: 244-265). The lack of effective screening and treatment strategies is a major reason for the significantly higher cervical cancer rates in developing countries compared with developed countries.
Screening efforts have relied largely on the Pap smear, a laboratory test developed in the 1940s to detect abnormal cervical cells. The test has achieved tremendous success in industrialized countries that offer periodic, high-quality screening. But Pap smear programs are complex and costly to run and have failed to reach a significant proportion of women in developing countries where health systems and infrastructure are weak. Importantly, in some countries women do not perform or consent to the Pap smear procedure due to cultural restrictions. Furthermore, there are analytical problems associated with Pap smear test. Pap smear does not detect all cases of cervical dysplasia or premalignancy. The current acceptable rate for false negatives for a test that guides physician to make a medical recommendation is approximately 5-10% but recent studies suggest that the actual rate of Pap smear may be much higher (Nanda K. et al., 2000, Ann Intern Med. 132:810-819; Kulasingam S. et al., 2002, JAMA. 288:1749-1757). The Pap smear defines approximately 7-8% of cases as atypical squamous cells of undetermined significance (ASCUS). In an additional 20-30% of cases, the Pap smear may be insufficient for interpretation due to the presence of inflammatory cells. Currently, to overcome shortcomings associated with the Pap smear test more studies are underway for developing new analytically more reliable assays for early detection of cervix premalignant condition in women. One of the approaches, based on universally accepted connection between consistent HPV infection of cervix and development of invasive cervical cancer is directed to the detection of the virus.